1. Field of the Invention
The present invention generally relates to composing and playing multimedia documents with variable play times on a computer system and, more particularly, to composing and playing multimedia episodes in multimedia documents so that they are presented correctly in time when the document play time is varied.
2. Background Description
Electronic multimedia documents have become a popular media for storing multimedia documents such as encyclopedias and the like since this media is capable of storing a large amount of data, including text, graphics, action video, sound, and the like, which when combined form a multimedia document. The user of a multimedia document typically presents or receives multimedia information called fragments, segments, or multimedia objects, hereinafter called episodes, through the computer input or output, respectively. Generally, these multimedia episodes include information having a sensory quality that can take the form of audio and visual information like audio and video clips, musical recordings, speech, typed text, still picturers, drawings, animation, choreographed dance steps, and the like.
Episodes that are presented as output of the computer are said to be "played". A visual output is played as a display, and an audio output is played as sound, sometimes accompanying a display. To compose or play a multimedia document, the computer user must select one or more episodes and play them in a particular order, and the order may be sequential, simultaneous or overlapping. Multimedia documents are called stories when they have related episodes that are organized and/or played with some sort of temporal constraints.
While composing or playing stories with a few number of episodes may be relatively easy, some prior art methods are incapable of composing or playing stories with a very large number of episodes. In addition, some prior art methods do not provide a way to schedule episodes that may be played in a variable time duration. Those prior art methods that do provide a way to schedule episodes of variable play time do not permit a user to constrain the global play time; i.e., the time that the entire story takes to play. Further, the prior art does not evenly distribute the variation of the difference between the optimal episode play time and the scheduled episode play time during the playing of the story.